Help create an inverse Trigger!

BMXTRIX

BMXTRIX

Audioholic Warlord
Guys, this is kind of a kick up, but how is something like this in such a world as ours?

I haven't messed with relays, as I can program them internally to a Crestron environment, but am more curious.

If I take the 12v trigger out from a AVR (for example) into the blue/green connection points of the relay, would that then open/close the connection outputs on the unit? So, red/black would be opened or closed respectively with 12v input?

It appears those relays can handle a ton of power on the output side of the connection, which makes sense to me. But, is there any lower-end limitation to what power can go through that relay? Could it just be a USB 5v power connection which is triggered by it?

Just hoping to expand my knowledge a bit. Thanks!
 
highfigh

highfigh

Audioholic Slumlord
I thought I had posted this link here... Clearly not. *blushes

All pertinent info is on pages 7 and 8 regarding the SMPS Standby Mode and Connector Pinouts.
6.1 shows that removing the voltage will take the power supply out of standby, so your initial post is correct. The Bosch-style relay will make this happen, or you could use a FET to do this, but it's a bit more complex.

OTOH, THEY could have made it easier by using a trigger voltage at system turn on to take it out of standby- maybe you could contact them to explain that AVRs have a +12VDC output trigger and they can change it for future shipments.
 
highfigh

highfigh

Audioholic Slumlord
Guys, this is kind of a kick up, but how is something like this in such a world as ours?

I haven't messed with relays, as I can program them internally to a Crestron environment, but am more curious.

If I take the 12v trigger out from a AVR (for example) into the blue/green connection points of the relay, would that then open/close the connection outputs on the unit? So, red/black would be opened or closed respectively with 12v input?

It appears those relays can handle a ton of power on the output side of the connection, which makes sense to me. But, is there any lower-end limitation to what power can go through that relay? Could it just be a USB 5v power connection which is triggered by it?

Just hoping to expand my knowledge a bit. Thanks!
Going by the diagram, it appears to be similar in function to the relay I have been writing about- the connections are internal and can't be seen; black is common to S1 and S2. Applying voltage to Green/Blue is the same as using 85 and 86 on the relay but the current used by this makes me think it has a coil that is more efficient.

As long as contact has been made (whether physical or if it uses a FET-type device), the current can be as low as needed by the device being powered.
 
ryanosaur

ryanosaur

Audioholic Warlord
Good stuff here, guys. Thank you! I’m not ghosting this, just been busy with a new project that came in.

@highfigh just looking for clarification on one question: the Bosch relays say a 14v signal is required to trigger the relay, iirc; that would mean the signal from the AVR may not be strong enough to throw the switch, correct?
 
Eppie

Eppie

Audioholic Samurai
@BMXTRIX as highfigh mentioned, current can be as low as required, you just can't exceed the max rating. Only caveat I would add is that at very low voltages a mechanical switch like a relay can produce some "bounce" in the signal, so it's not an exact square wave but can have some ripple at the transition. This can cause issues with sensitive circuitry that has tight tolerances. In such a case an electronic switch is required.
EDIT: Yes, green blue connects to the coil which is the trigger. SW1 is normally open, SW2 is normally closed.

@ryanosaur if it's a car relay then I would expect it work with a 12V signal to the coil. Lots of 12V relays out there, like this one from PartsExpress.
 
highfigh

highfigh

Audioholic Slumlord
Good stuff here, guys. Thank you! I’m not ghosting this, just been busy with a new project that came in.

@highfigh just looking for clarification on one question: the Bosch relays say a 14v signal is required to trigger the relay, iirc; that would mean the signal from the AVR may not be strong enough to throw the switch, correct?
They show that because, while car batteries are called '12V', the charging system is actually putting out 14.4V when the engine is operating above about 2000RPM. They work fine with a half-dead car battery and wall wart power supplies to use the DC trigger output as long as t hatcan support 150mA or more. The ones on Amazon that have the green/blue wires need less current and because they're in a box, that would be an easy way to get what you need without needing to mess around with "I have a relay- what do I do with it after it's wired?".

I have used these relays with AVR triggers after measuring the current- they work fine. The AVR is designed to drive 150mA and if the load is excessive, it just interrupts the current from the trigger- it won't damage anything.

If you have been in a home theater where a projection screen was used, you might notice a quiet click in the screen's housing when the system turns on- that's a relay, likely an Omron or equivalent because it needs less space than the Bosch style. One reason I mentioned the Bosch is that A) I have experience with them and B) the wiring diagram is often shown on the housing.
 
highfigh

highfigh

Audioholic Slumlord
@BMXTRIX as highfigh mentioned, current can be as low as required, you just can't exceed the max rating. Only caveat I would add is that at very low voltages a mechanical switch like a relay can produce some "bounce" in the signal, so it's not an exact square wave but can have some ripple at the transition. This can cause issues with sensitive circuitry that has tight tolerances. In such a case an electronic switch is required.
EDIT: Yes, green blue connects to the coil which is the trigger. SW1 is normally open, SW2 is normally closed.

@ryanosaur if it's a car relay then I would expect it work with a 12V signal to the coil. Lots of 12V relays out there, like this one from PartsExpress.
I addressed the spike in my first post- some relays have a diode to suppress it. Doesn't matter which type of wave it is, it's transient and can cause issues, but at </= 150mA, the spike won't be large.
 
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